scholarly journals Could Supercritical Extracts from the Aerial Parts of Helianthus salicifolius A. Dietr. and Helianthus tuberosus L. Be Regarded as Potential Raw Materials for Biocidal Purposes?

Agriculture ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
Anna Malm ◽  
Agnieszka Grzegorczyk ◽  
Anna Biernasiuk ◽  
Tomasz Baj ◽  
Edward Rój ◽  
...  

Extracts from the June collection of aerial parts of Helianthus salicifolius A. Dietr and Helianthus tuberosus L. were obtained using carbon dioxide supercritical fluid extraction with water as co-solvent. The antimicrobial effect in vitro of these extracts was then determined against reference species of bacteria, as well as against fungi (represented by Candida spp.). Both extracts were found to possess antimicrobial activity, with MIC = 0.62–5 mg mL−1 for bacteria and MIC = 5–10 mg mL−1 for yeasts, and both extracts demonstrated suitable bactericidal and fungicidal effect. The highest activity was observed against S. aureus ATCC 29213 (MIC = 0.62 mg mL−1 for H. salicifolius extract; MIC = 2.5 mg mL−1 for H. tuberosus extract) as confirmed by time–kill assay. Higher antioxidant activity was found for H. tuberosus extract (EC50 = 0.332 mg mL−1) as compared to that of H. salicifolius (EC50 = 0.609 mg mL−1). The total polyphenol content (TPC) expressed as gallic acid equivalents (GAE) was 13.75 ± 0.50 mg GAE g−1 of H. salicifolius extract and 33.06 ± 0.80 mg GAE g−1 of H. tuberosus extract. There was a relationship between the antioxidant potential of both extracts and TPC, but not between antistaphylococcal activity and TPC. The ATIR–FTIR spectra of both extracts showed similar main vibrations of the functional groups typical for phytoconstituents possessing bioactivity. The obtained data suggest potential application of these extracts as natural antioxidants and preparations with biocidal activity. Additionally, both extracts may be regarded as potential natural conservants in cosmetics, as well as natural preservatives in food.

Author(s):  
Anna Malm ◽  
Agnieszka Grzegorczyk ◽  
Anna Biernasiuk ◽  
Tomasz Baj ◽  
Edward Rój ◽  
...  

The extracts from the aerial parts of Helianthus salicifolius A. Dietr and Helianthus tuberosus L. collected in June were obtained using carbon dioxide supercritical fluid extraction with water as co-solvent. The antimicrobial activity in vitro of these extracts were determined against the reference species of Gram-positive and Gram-negative bacteria as well as fungi, representing by the yeast species of Candida spp. The following parameters were estimated: minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC). Both extracts were found to possess antimicrobial activity with MIC = 0.62-5 mg mL-1 for bacteria and MIC = 5-10 mg mL-1 for yeasts, showing bactericidal (MBC/MIC = 2-4) or fungicidal effect (MFC/MIC = 1-2 ). The highest activity was observed against S. aureus ATCC 29213 (MIC = 0.62 mg mL-1 for H. salicifolius extract; MIC = 2.5 mg mL-1 for H. tuberosus extract). Bactericidal effect of both extracts against S. aureus ATCC 29213 was confirmed by time-kill assay. Higher antioxidant activity was found for H. tuberosus extract (EC50 = 0.332 mg mL-1) as compared to that of H. salicifolius (EC50 = 0.609 mg mL-1). The total polyphenol content (TPC) expressed as gallic acid equivalents (GAE) was 13.75 ± 0.50 mg GAE (g of H. salicifolius extract)-1 and 33.06 ± 0.80 mg GAE (g of H. tuberosus extract)-1. There was a correlation between the antioxidant potential of both extracts and TPC but not between antistaphylococcal activity and TPC. The obtained data suggest potential application of these extracts as the natural preparations with the biocidal activity, including those with antistaphylococcal activity. Besides, both extracts may be regarded as potential natural conservants in cosmetics as well as natural preservatives in food.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1176
Author(s):  
Vanesa Pérez-Laguna ◽  
Yolanda Barrena-López ◽  
Yolanda Gilaberte ◽  
Antonio Rezusta

Candidiasis is very common and complicated to treat in some cases due to increased resistance to antifungals. Antimicrobial photodynamic therapy (aPDT) is a promising alternative treatment. It is based on the principle that light of a specific wavelength activates a photosensitizer molecule resulting in the generation of reactive oxygen species that are able to kill pathogens. The aim here is the in vitro photoinactivation of three strains of Candida spp., Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258, using aPDT with different sources of irradiation and the photosensitizer methylene blue (MB), alone or in combination with chlorhexidine (CHX). Irradiation was carried out at a fluence of 18 J/cm2 with a light-emitting diode (LED) lamp emitting in red (625 nm) or a white metal halide lamp (WMH) that emits at broad-spectrum white light (420–700 nm). After the photodynamic treatment, the antimicrobial effect is evaluated by counting colony forming units (CFU). MB-aPDT produces a 6 log10 reduction in the number of CFU/100 μL of Candida spp., and the combination with CHX enhances the effect of photoinactivation (effect achieved with lower concentration of MB). Both lamps have similar efficiencies, but the WMH lamp is slightly more efficient. This work opens the doors to a possible clinical application of the combination for resistant or persistent forms of Candida infections.


2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S422-S422
Author(s):  
Heather Pomerantz ◽  
Miriam Beckius ◽  
Dana Blyth ◽  
Kevin S Akers ◽  
David R Tribble ◽  
...  

Abstract Background Fungal infections are a critical cause of morbidity and mortality in burn patients. In addition to debridement and systemic antifungal therapy, various topical adjuncts have been used, and topical burn care is a key component of infection prevention and treatment. Cerium nitrate (CN) has been used in combination with silver sulfadiazine (SS) in burn care. Previous studies showed that CN had bacteriostatic activity, and suggested anti-biofilm activity against Candida biofilms. In this study, we evaluated the in vitro activity of CN against fungal isolates associated with combat-related injuries. Methods The efficacy of CN was evaluated against 14 mold (three Aspergillus spp., two Fusarium spp., five different mucormycetes, two Bipolaris spp., one Alternaria spp., one Exophiala spp.) and 21 Candida spp. isolates collected as part of the Trauma Infectious Disease Outcomes Study. Fungicidal activity of various concentrations of CN (2.2%, 1%, 0.5% and 0.2%) was determined using an established time-kill assay. Standard conidia/cell suspensions were prepared according to Clinical and Laboratory Standards Institute guidelines and then exposed to the CN solutions for 24 hours. At different times (0, 5, 15, 30 minutes, 1, 1.5, 3, 6, 12, and 24 hours) aliquots were plated and incubated at 35ºC. Colony forming unit (CFU) counts were determined after 24 hours incubation or after an appropriate time for slow growing molds. Results All mold isolates had persistent growth at 24 hours with most having no significant change in colony counts over the 24-hour period. The only exception was Mucor circinelloides, which appeared to have a time-dependent reduction in CFUs at 24 hours for all CN concentrations. Exophiala did not grow as well in CN solutions compared with the control (mean 65 vs. 28.2 CFUs with a difference of mean 37.4 CFUs, P = 0.0001), but this was not time or concentration dependent. All yeast species showed a time-dependent killing after 6–12 hours. Conclusion CN demonstrated time-dependent killing of the yeasts. However, very little activity was observed against the tested molds. Since CN is often used in combination with SS there might be a synergistic effect against molds. Further research will evaluate higher concentrations of CN and its toxicity for cells and tissue. Disclosures All authors: No reported disclosures.


2011 ◽  
Vol 56 (3) ◽  
pp. 1584-1587 ◽  
Author(s):  
Johanne Blais ◽  
Stacey R. Lewis ◽  
Kevin M. Krause ◽  
Bret M. Benton

ABSTRACTTD-1792 is a new multivalent glycopeptide-cephalosporin antibiotic with potent activity against Gram-positive bacteria. Thein vitroactivity of TD-1792 was tested against 527Staphylococcus aureusisolates, including multidrug-resistant isolates. TD-1792 was highly active against methicillin-susceptibleS. aureus(MIC90, 0.015 μg/ml), methicillin-resistantS. aureus, and heterogeneous vancomycin-intermediateS. aureus(MIC90, 0.03 μg/ml). Time-kill studies demonstrated the potent bactericidal activity of TD-1792 at concentrations of ≤0.12 μg/ml. A postantibiotic effect of >2 h was observed after exposure to TD-1792.


2001 ◽  
Vol 45 (3) ◽  
pp. 927-931 ◽  
Author(s):  
Alexander A. Firsov ◽  
Irene Y. Lubenko ◽  
Yury A. Portnoy ◽  
Stephen H. Zinner ◽  
Sergey N. Vostrov

ABSTRACT Most integral endpoints of the antimicrobial effect are determined over an arbitrarily chosen time period, such as the dosing interval (τ), regardless of the actual effect duration. Unlike the τ-related endpoints, the intensity of the antimicrobial effect (I E) does consider its duration—from time zero to the time when bacterial counts on the regrowth curve achieve the same maximal numbers as in the absence of the antimicrobial. To examine the possible impact of this fundamental difference on the relationships of the antimicrobial effect to the ratio of the area under the concentration-time curve (AUC) to the MIC, a clinical isolate ofStaphylococcus aureus was exposed to simulated gemifloxacin pharmacokinetics over a 40-fold range of AUC/MIC ratios, from 11 to 466 h. In each run, I E and four τ-related endpoints, including the area under the time-kill curve (AUBC), the area above the curve (AAC), the area between the control growth and time-kill curves (ABBC), and the ABBC related to the area under the control growth curve (AUGC), were calculated for τ = 24 h. Unlike the I E, which displayed pseudolinear relationships with the AUC/MIC ratio; each τ-related endpoint showed a distinct saturation at potentially therapeutic AUC/MIC ratios (116 to 466 h) when the antimicrobial effect persisted longer than τ. This saturation results from the underestimation of the true effect and may be eliminated if ABBC, AAC, and AUBC (but not AUGC) are modified and determined in the same manner as the I E to consider the actual effect duration. These data suggest a marginal value of the τ-related endpoints as indices of the total antimicrobial effect. Since all of them respond to AUC/MIC ratio changes less than theI E, the latter is preferable in comparative pharmacodynamic studies.


2019 ◽  
Vol 6 (1) ◽  
pp. 8-16
Author(s):  
Saber Boutellaa ◽  
Amar Zellagui ◽  
Mehmet Öztürk ◽  
Chawki Bensouici ◽  
Özge Tokul Ölmez ◽  
...  

Abstract In this study, phenolic compounds from Crithmum maritimum L. n-butanol soluble fraction were quantified and identified spectrophotometrically and by using HPLC-DAD technics. They equally investigated for their antioxidant potential utilizing six in vitro assays: DPPH•, ABTS•+, O2•−, Bleaching of β-carotene in linoleic acid, CUPRAC and Ferric reducing power. High amounts of total phenolics and flavonoids were recorded: 161.57± 0.479 μg GAeq.mg−1 and 31.56± 0.291 μg Qeq.mg−1 respectively. Nine compounds among them hydroxicinnamic acid and hydroxybenzoic acid derivatives, coumarins and flavonoids were identified. Chlorogenic acid known for their various pharmacological properties was detected as major compound of the extract. Rutin, vanillin, trans-2-hydroxycinnamic acid, ellagic acid, ferrulic acid, 6,7 dihydroxy coumarin, methyl 1,4 benzoquinone and trans-cinnamic acid were also detected. The extract was found to exhibit strong antioxidant capacities in all systems. Based on these results, it is right to conclude the n-butanol extract is promising source of natural antioxidants.


2007 ◽  
Vol 51 (4) ◽  
pp. 1508-1511
Author(s):  
Kim Credito ◽  
Genrong Lin ◽  
Peter C. Appelbaum

ABSTRACT Time-kill synergy studies testing in vitro activity of DX-619 alone and with added vancomycin, teicoplanin, or linezolid against 101 Staphylococcus aureus strains showed synergy between DX-619 and teicoplanin at 12 to 24 h in 72 strains and between DX-619 and vancomycin in 28 strains. No synergy was found with linezolid, and no antagonism was observed with any combination.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5760
Author(s):  
Elda M. Melchor-Martínez ◽  
Juan F. Tamez-Fernández ◽  
Gloria María González-González ◽  
David A. Silva-Mares ◽  
Noemí Waksman-Minsky ◽  
...  

Candida albicans is the most commonly implicated agent in invasive human fungal infections. The disease could be presented as minimal symptomatic candidemia or can be fulminant sepsis. Candidemia is associated with a high rate of mortality and high healthcare and hospitalization costs. The surveillance programs have reported the distribution of other Candida species reflecting the trends and antifungal susceptibilities. Previous studies have demonstrated that C. glabrata more frequently presents fluconazole-resistant strains. Extracts from Mexican plants have been reported with activity against pulmonary mycosis, among them Colubrina greggii. In the present study, extracts from the aerial parts (leaves, flowers, and fruits) of this plant were evaluated against clinical isolates of several species of Candida (C. albicans, C. glabrata, C. parapsilosis, C. krusei, and C. tropicalis) by the broth microdilution assay. Through bioassay-guided fractionation, three antifungal glycosylated flavonoids were isolated and characterized. The isolated compounds showed antifungal activity only against C. glabrata resistant to fluconazole, and were non-toxic toward brine shrimp lethality bioassay and in vitro Vero cell line assay. The ethyl acetate and butanol extracts, as well as the fractions containing the mixture of flavonoids, were more active against Candida spp.


1998 ◽  
Vol 42 (3) ◽  
pp. 659-665 ◽  
Author(s):  
Alexander A. Firsov ◽  
Alexander A. Shevchenko ◽  
Sergey N. Vostrov ◽  
Stephen H. Zinner

ABSTRACT Earlier efforts to search for pharmacokinetic and bacteriological predictors of fluoroquinolone antimicrobial effects (AMEs) have resulted in conflicting findings. To elucidate whether these conflicts are real or apparent, several predictors of the AMEs of two pharmacokinetically different antibiotics, trovafloxacin (TRO) and ciprofloxacin (CIP), as well as different dosing regimens of CIP were examined. The AMEs of TRO given once daily (q.d.) and CIP given q.d. and twice daily (b.i.d.) against Escherichia coli,Pseudomonas aeruginosa, and Klebsiella pneumoniae were studied in an in vitro dynamic model. Different monoexponential pharmacokinetic profiles were simulated with a TRO half-life of 9.2 h and a CIP half-life of 4.0 h to provide similar eightfold ranges of the area under the concentration-time curve (AUC)-to-MIC ratios, from 54 to 432 and from 59 to 473 (μg · h/ml)/(μg/ml), respectively. In each case the observation periods were designed to incorporate full-term regrowth phases in the time-kill curves, and the AME was expressed by its intensity (IE ; the area between the control growth and time-kill and regrowth curves up to the point at which the viable counts of regrowing bacteria are close to the maximum values observed without drug). Species-independent linear relationships were established between IE and log AUC/MIC, log AUC above MIC (log AUCeff), and time above the MIC (T eff). Specific and nonsuperimposedIE versus log AUC/MIC or log AUCeffrelationships were inherent in each of the treatments: TRO given q.d. (r 2 = 0.97 and 0.96), CIP given q.d. (r 2 = 0.98 and 0.96), and CIP given b.i.d. (r 2 = 0.95 and 0.93). This suggests that in order to combine data sets obtained with individual quinolones to examine potential predictors, one must be sure that these sets may be combined. Unlike AUC/MIC and AUCeff, the IE -T effrelationships plotted for the different quinolones and dosing regimens were nonspecific and virtually superimposed (r 2 = 0.95). Hence, AUC/MIC, AUCeff, and T eff were equally good predictors of the AME of each of the quinolones and each dosing regimen taken separately, whereas T eff was also a good predictor of the AMEs of the quinolones and their regimens taken together. However, neither the quinolones nor the dosing regimens could be distinguished solely on the basis of T eff, whereas they could be distinguished on the basis of AUC/MIC or AUCeff. Thus, two types of predictors of the quinolone AME may be identified: intraquinolone and/or intraregimen predictors (AUC/MIC, AUCeff and Teff) and an interquinolone and interregimen predictor (T eff). T eff may be able to accurately predict the AME of one quinolone on the basis of the data obtained for another quinolone.


1996 ◽  
Vol 40 (3) ◽  
pp. 627-632 ◽  
Author(s):  
K J Madaras-Kelly ◽  
B E Ostergaard ◽  
L B Hovde ◽  
J C Rotschafer

Several investigators have suggested that the 24-h area under the concentration-time curve (AUC)/MIC ratio (AUC/MIC24 or AUIC24) can be used to make comparisons of antimicrobial activity between fluoroquinolone antibiotics. Limited data exist regarding the generic predictive ability of AUC/MIC24 for the antimicrobial effects of fluoroquinolones. The purposes of the present investigation were to determine if the AUC/MIC24 can be used as a generic outcome predictor of fluoroquinolone antibacterial activity and to determine if a similar AUC/MIC24 breakpoint can be established for different fluoroquinolones. Using an in vitro pharmacodynamic model, 29 duplicate concentration time-kill curve experiments simulated AUC/MIC24s ranging from 52 to 508 SIT-1.h (inverse serum inhibitory titer integrated over time) with ciprofloxacin or ofloxacin against three strains of Pseudomonas aeruginosa. Each 24-h experiment was performed in cation-supplemented Mueller-Hinton broth with a starting inoculum of 10(6) CFU/ml. At timed intervals cation-supplemented Mueller-Hinton broth samples were collected for CFU and fluoroquinolone concentration determinations. Transformation of bacterial counts into the cumulative bacterial effect parameter of the 24-h area under the effect curve (AUEC24) was performed for each concentration time-kill curve. Multivariate regression analysis was used to compare pharmacodynamic predictors (AUC/MIC24, 24-h AUC, peak concentration [Cmax] to MIC ratios [Cmax:MIC], etc.) with ln AUEC24. To identify threshold breakpoint AUC/MIC24s, AUEC24s were stratified by the magnitude of AUC/MIC24 into subgroups, which were analyzed for differences in antibacterial effect. The Kruskal-Wallis test and subsequent Tukey's multiple comparison test were used to determine which AUC/MIC subgroups were significantly different. Multiple regression analysis revealed that only AUC/MIC24 (r2 = 0.65) and MIC (r2 = 0.03) were significantly correlated with antibacterial effect. At similar AUC/MIC24s, yet different MICs, Cmaxs, or elimination half-lives, the AUEC24s were similar for both fluoroquinolones. The relationship between AUC/MIC24 and ln AUEC24 was best described by a sigmoidal maximal antimicrobial effect (Emax) model (r2 = 0.72; Emax = 9.1; AUC/MIC50 = 119 SIT-1.h; S = 2.01 [S is an exponent that reflects the degree of sigmoidicity]). Ciprofloxacin-bacteria AUC/MIC24 values of < 100 SIT-1.h were significantly different (P < 0.05) from the AUC/MIC24 values of > 100 SIT-1.h. An ofloxacin AUC/MIC24 of > 100 SIT-1.h and an AUC/MIC24 of < 100 SIT-1.h exhibited a trend toward a significant difference (P > 0.05 but < 0.1). The inverse relationship between drug exposure and MIC increase postexposure was described by a sigmoidal fixed Emax model (AUC/MIC24, r2 = 0.40; AUC/MIC50 = 95 SIT-1.h; S = 1.97; Cmax:MIC, r2 = 0.41; Cmax:MIC50 = 7.3; S = 2.01). These data suggest that AUC/MIC24 may be the most descriptive measurement of fluoroquinolone antimicrobial activity against P. aeruginosa, that ofloxacin and ciprofloxacin have similar AUC/MIC24 threshold breakpoints at approximately 100 SIT-1.h, that the concentration-dependent selection of resistant organisms may parallel the threshold breakpoint of the antimicrobial effect, and that AUC/MIC24 generically describes the antibacterial effects of different fluoroquinolones.


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